Nav bar - responsivness

Hello,

I’m currently creating my site with Moesia, and I am having some difficulties with the menu/nav bar when reducing the window’s size.

The menu disappears and I need to enlarge the window to make it reappear.

Here’s the link to the site: http://singularte.mywebcommunity.org/

Thank you for your help

Managed to fix, sorry for the inconvenience.
Could you please delete my post? thanks